Lehmberg hired a special prosecutor, Michael McCrum, to pursue the case against Perry. Since September of last year the public integrity unit has operated out of the Texas Rangers instead of the Travis County District Attorney’s Office, so blatantly political attacks like this shouldn’t happen again. It still took Perry two years to clear his name.

Better to lose to a true enemy whose policies you can fight and repudiate, rather than to a false friend whose schemes will drag you down with him. This is a painful choice, but it also embraces realism while protecting the possibility of recovery in the future. The need to live to fight another day is why conservatives should adopt a Hamilton Rule if, God forbid, the choice comes down to Hillary and Trump.